CN110333281A

CN110333281A - A method of it is receiving Ratio of Lead Isotopes in inductivity coupled plasma mass spectrometry measurement deposit more

Info

Publication number: CN110333281A
Application number: CN201910612814.3A
Authority: CN
Inventors: 张辉; 刘季花; 张俊; 何连花; 张颖; 朱爱美
Original assignee: First Institute of Oceanography MNR
Current assignee: First Institute of Oceanography MNR
Priority date: 2019-07-09
Filing date: 2019-07-09
Publication date: 2019-10-15
Anticipated expiration: 2039-07-09
Also published as: CN110333281B

Abstract

The method for more receiving Ratio of Lead Isotopes in inductivity coupled plasma mass spectrometry measurement deposit the present invention provides one kind rejects gravel and animals and plants remnant, is ground to 100 ~ 200 mesh, obtains sample the method includes wet sample to be freeze-dried or dry；By sample except dissolving in polytetrafluoroethylene (PTFE) cast bottle after carbonate, lysate is obtained；Lysate is separated and purified using ionic energy transfer column, prepare liquid is obtained；Measure Ratio of Lead Isotopes in the prepare liquid using the inductively coupled plasma mass spectrometries that receive more.The present invention uses homemade ionic energy transfer column, disposable, and anti-cross-contamination while reduces cost.Method provided by the invention can be widely applied to the research of lead isotope in deposit, can quickly, stablize, accurately measure Ratio of Lead Isotopes.

Description

It is a kind of to receive Lead Isotope Ratios in inductivity coupled plasma mass spectrometry measurement deposit more The method of value

Technical field

The invention belongs to field of chemical detection, and in particular to a kind of more reception inductivity coupled plasma mass spectrometries measurement depositions The method of Ratio of Lead Isotopes in object.

Background technique

In nature lead with²⁰⁴Pb、²⁰⁶Pb、²⁰⁷Pb、²⁰⁸The presence of tetra- kinds of isotopes of Pb, relative abundance is respectively 1.48%, 23.6%, 22.6%, 52.3%, it removes²⁰⁴Pb be the non-radioactive origin cause of formation outside, other respectively by²³⁸U、²³⁵U、²³²Th decay generates, and is studying When lead isotope Plantago fengdouensis with²⁰⁴Pb as comparison basis, measure other each isotopes with²⁰⁴The ratio of Pb.

Inductivity coupled plasma mass spectrometry is the inorganic elements to grow up the 1980s and isotope analysis test Technology, it is with unique interfacing by the sensitive quick scanning of the thermal ionization characteristic of inductively coupled plasma body and mass spectrograph The advantages of combine and formed the analytical technology of high sensitivity a kind of.And it receives inductive plasma mass spectrograph more and passes through changeable colour Zoom ion lens is dissipated, on the stationary detectors array of multiple Faraday cups and multiple Ion Counting multipliers, is realized from lithium To uranium isotope while measure.Have become a kind of the important of the isotope abundance that can quickly measure in liquid and solid Analysis tool.

Summary of the invention

The object of the present invention is to provide a kind of inductivity coupled plasma mass spectrometries that receive more to measure the same position of lead in deposit The method of plain ratio can fast and accurately measure Ratio of Lead Isotopes, and the present invention uses homemade ionic energy transfer column, can To reduce cost while anti-cross-contamination.

For achieving the above object, the present invention is achieved by the following scheme:

The present invention provides one kind to receive the method that inductivity coupled plasma mass spectrometry measures Ratio of Lead Isotopes in deposit more, It the described method comprises the following steps:

Wet sample is freeze-dried or is dried by step 1, rejects gravel and animals and plants remnant, and grinding obtains sample；

Sample is put into polytetrafluoroethylene (PTFE) cast bottle by step 2, and nitrate acid and hydrofluoric acid-perchloric acid is sequentially added into sample and is carried out Dissolution, obtains lysate；

Lysate is successively carried out primary column excessively using ionic energy transfer column and crosses column twice by step 3, obtains prepare liquid；

Step 4 measures Ratio of Lead Isotopes in the prepare liquid using the inductivity coupled plasma mass spectrometries that receive more.

Further: the step 2 further includes being put into polytetrafluoroethylene (PTFE) cast bottle after the sample is removed carbonate.

It is further: the ionic energy transfer column the preparation method comprises the following steps:

Dropper upper end is removed, lower end is cut to wedge shape, using punch by hydrophily sieve plate be made diameter greater than dropper lower part it is straight Round sieve plate is filled in dropper lower end by the round sieve plate of diameter, will be sealed around sieve plate using dropper retractility.

Further: the dropper material is LDPE, and the hydrophily sieve plate material is PTFE, and the aperture of the sieve plate is small In 50 microns.

It is further: the fill method of the ionic energy transfer column are as follows:

A, with ionic energy transfer column 3 ~ 4 times of the dipped hydrochloric acid solution of ultrapure water；

B, 8 anion exchange resin of AG1 ' is used into hydrochloric acid solution soaked overnight, with ultrapure water to neutrality；

C, add edge on ultrapure water to ionic energy transfer column, add 8 anion exchange resin of AG1 ', add to 8 anion of AG1 ' After exchanger resin sedimentation at the slope of ionic energy transfer column lower part.

It is further: the primary specific steps for crossing column are as follows:

A, after regenerating ionic energy transfer column with hydrochloric acid solution plus HBr solution is until balance；

B, lysate is centrifuged, Aspirate supernatant drop is eluted on ionic energy transfer column；

C, leacheate is received using hydrochloric acid solution, is evaporated and is added the dissolution of HBr solution, obtain once crossing the solution after column.

It is further: described secondary the step of crossing column are as follows:

B, the solution drop after primary column excessively is eluted on ionic energy transfer column；

C, leacheate is received using hydrochloric acid solution, obtains prepare liquid.

Further: the solution used that elutes is 0.5 ~ 0.7mol/LHBr solution, is eluted 3 ~ 4 times.

Further: the concentration of the hydrochloric acid solution is 6 ~ 7mol/L.

It is further: described to measure Lead Isotope Ratios in the prepare liquid using the inductivity coupled plasma mass spectrometries that receive more It is worth specific steps are as follows:

Using NBS982 as standard substance, the isotopic composition of Tl solution is demarcated；

Prepare liquid is evaporated, 2%HNO is added₃Dissolution, with the 2%HNO that calibrated Tl isotopic standard solution is added₃Dilution, with SRM981 is standard test Pb isotopic ratio；

Pass through measurement²⁰²Hg is used²⁰²Hg/²⁰⁴The natural abundance ratio of Hg carries out interference correction, eliminates²⁰⁴Hg pairs²⁰⁴The interference of Pb.

Further: the dropper is 2mL, is cut to wedge shape at the 3cm of lower part, round sieve plate is filled in dropper lower end 2.5cm Place.

Compared with prior art, it advantages of the present invention and has the technical effect that

1, the method for Ratio of Lead Isotopes passes through the type for changing acid and acidity certainly in measurement deposit provided by the invention Pb is isolated and purified on 8 anion exchange resin of AG1 ' processed, measures isotope ratio with the inductivity coupled plasma mass spectrometries that receive more Value.

2, the present invention uses homemade ionic energy transfer column, disposable, and anti-cross-contamination while reduces cost.

3, method provided by the invention can be widely applied to the research of lead isotope in deposit, can quickly, stablize, Accurately measurement Ratio of Lead Isotopes.

Detailed description of the invention

Fig. 1 is ionic energy transfer column schematic diagram, and wherein a is the height and position of potting resin, and b is the friendship of 8 anion of AG1 ' Resin is changed, c is hydrophily sieve plate, and h1 is the distance of the height and position of dropper lower end to potting resin, and h2 is hydrophily sieve plate Position to potting resin height and position distance.

Specific embodiment

With reference to embodiments by the technical scheme of the present invention will be explained in further detail.

Embodiment 1

One, reagent and material

Nitric acid (HNO₃, excellent pure grade)；Hydrochloric acid (HCl, excellent pure grade)；Nitric acid (HNO₃, it is ultrapure, purified through second distillation)；Hydrochloric acid (HCl, it is ultrapure, purified through second distillation, through acid base titration accurate calibration concentration)；Hydrofluoric acid (HF, it is ultrapure, it is pure through second distillation Change)；Hydrobromic acid (HBr, it is ultrapure, purified through 8 resin anion (R.A.) of AG1 ', through acid base titration accurate calibration concentration)；Ultrapure water (> 18.2 M Ω)；Dehydrated alcohol (excellent pure grade)；

Polytetrafluoroethylene (PTFE) cast bottle

8 anion exchange resin of AG1 '；

Pb isotopic standard solution: SRM981/NBS981/NBS982；

Tl isotopic standard solution；

Liquid-transfering gun: 1 mL, 5 mL；The other common containers in laboratory, material.

250 μ L ionic energy transfer columns, as shown in Figure 1, specific the preparation method comprises the following steps: using commercially available 2mL high-quality dropper (material LDPE) removes dropper top, and (h1 3cm) is cut to wedge shape at the 3cm of lower part, using punch by hydrophily sieve plate The round sieve plate that diameter is slightly larger than dropper lower diameter is made in (material PTFE, aperture < 50 micron), and round sieve plate is filled in drop At the 2.5cm of pipe lower end (h2 2.5cm), it will be sealed around sieve plate using dropper retractility.

Two, preparation of reagents

HNO₃(1:1): by 1000 mL HNO₃(excellent pure grade) is added in the polytetrafluoroethylene beaker equipped with 1000 mL ultrapure waters；

HCl(1:1 it): 500 mL HCl(are ultrapure) is added in the polytetrafluoroethylene beaker equipped with 500 mL ultrapure waters；

HCl(0.25mol/L it): concentration being demarcated according to soda acid HCl(is ultrapure) is put with ultrapure water accurate dilutions to 0.25mol/L It is spare in polytetrafluoroethylene (PTFE) reagent bottle；

HCl(6mol/L poly- four): concentration being demarcated according to soda acid HCl(is ultrapure) are put in 6mol/L with ultrapure water accurate dilutions It is spare in vinyl fluoride reagent bottle；

HBr(0.6mol/L): concentration being demarcated according to soda acid HBr(is ultrapure) ultrapure to be really diluted to 0.6mol/L with level, it is put in It is spare in polytetrafluoroethylene (PTFE) reagent bottle.

Three, instrument and equipment

Polytetrafluoroethylene (PTFE) cast bottle (7mL, 15mL)；Electric hot plate (polytetrafluorethylecoatings coatings)；(maximum speed is greater than supercentrifuge 10000 revs/min)；Ultra-clean experimental bench (hundred grades)；

Receive inductivity coupled plasma mass spectrometry (MC-ICP-MS), which has 12 Faraday cups and 3 Ion Countings more Device.Faraday cup measurement range is 1 mv to 20 V, and ion counter measurement range is 1 cps to 10 mV.By field quality The ion beam of dispersion is not required to adjust manually by two groups of electronic lens focusings to fixed Faraday cup and ion counter center Adjustment receiver position.Sample solution goes dissolving device to introduce mass spectrograph Faraday cup while receiving difference by DSN-100 type film Proton number Pb isotope.Every group of (block) data acquire 20 data points, and every time of integration is 20s, every group of data acquisition The background measurement of 20s is carried out before.

Four, vessel clean

1) label on the experimental ware to be cleaned is wiped with dehydrated alcohol, is rinsed 3 times with tap water.

2) experimental ware is put into ultrasonic cleaner, suitable tap water and detergent, ultrasound 30 at 60 DEG C is added Minute, it is rinsed 3 times with tap water, is then used ultrapure water 5-6 times.

3) suitable HNO is added as the case may be₃Then (1:1) is clamped in beaker with Special-purpose forceps are (acidproof) Experimental ware through having rinsed enters in beaker, allows the experimental ware that acid soak is all, is placed on electric hot plate and keeps the temperature 12 hours for 150 DEG C More than, after its cooling, with ultrapure water 5-6 times.

4) clean HNO is changed₃(1:1) repeats the above steps 3).

5) HCl(1:1 is added in each experimental ware), more than the amount of its volume half, lid is tightened, electric hot plate is placed in Upper 120 DEG C of heat preservations 12 hours or more, acid is poured out after cooling, with ultrapure water 5-6 times.

6) entered in beaker with the experimental ware that Special-purpose forceps clamping has been rinsed, ultrapure water is added to impregnate all testers Ware is placed on electric hot plate 100 DEG C of heat preservations 4 hours or more, uses ultrapure water 3 times after cooling.

7) clean experimental ware is placed in draught cupboard dry it is spare.

Five, receive the method for Ratio of Lead Isotopes in inductivity coupled plasma mass spectrometry measurement deposit more

Specifically includes the following steps:

1, the preparation of sample:

1) wet sample is placed in freeze drier and is freeze-dried or goes to wet sample in numbered evaporating dish, be placed in 60 DEG C of baking ovens Interior drying.

2) sample after drying is spread on clean polyethylene board, rejects gravel and the biggish animals and plants remnant of particle.

3) dry sample is mixed well with the sample that agate mortar is milled to all by 200 mesh, after grinding.

4) quartering division point takes the sample prepared, is put into sample sack, lab analysis is sent to measure.Remaining sample is set In paper bag, duplicate sample preservation is given over to.

2, the dissolution of sample

1) carbonate removal: weighing powder sample (200 mesh) 200-300mg or so in the test tube of 15ml, and 0.25mol/ is added LHCl(0.25mol/L 4h) is impregnated, the supernatant that inclines is centrifuged, washs centrifugation repeatedly with ultrapure water to neutrality, incline supernatant, stays It is spare to set sample；

2) sample dissolves:

A) sample after centrifugation is transferred in the polytetrafluoroethylene (PTFE) cast bottle of 15ml；

B) HNO is added along cast bottle wall₃(ultrapure) 2ml, slowly shakes to powder sample without agglomeration；(100 DEG C) of low temperature heating 12 Hour；

C) it is ultrapure that HF(is added) 2ml, it is increased to 160 DEG C and heats 3 days, during which often slowly shake cast bottle.

D) it uncaps and steams to remaining 1ml or so 200 ~ 400 ultrapure HClO of μ L of addition₄It covers, 170 DEG C of 12 h of heating.

E) it uncaps on electric hot plate 120 DEG C of heating, is evaporated sample solution, be warming up to 190 DEG C and rush to white cigarette and emit to the greatest extent, points 2 times Add 2mLHNO₃(ultrapure) catches up with HF and HClO excessive to the greatest extent₄Acid.

F) it is ultrapure that 1mLHCl(is added) it is evaporated after 100 DEG C of chlorinations afterwards.

G) be added 1mLHBr(0.6mol/L) afterwards 80 DEG C of brominations be evaporated.

H) 1mL 0.6HBr(0.6mol/L is added) it stands overnight, prepare Chemical Decomposition and purifying.

3, the filling of ionic energy transfer column

A) ionic energy transfer column clean: with the dipped HCl(6mol/L of ultrapure water repeated flushing) self-control ionic energy transfer column It 3-4 times, is placed on the resin pylon crossed through ultrapure water.

B) resin cleans: 8 anion exchange resin of AG1 ' (the ultrapure acid of 1:1 prepares chloroazotic acid) was impregnated in PFA bottle Night is immersed in spare in ultrapure water with ultrapure water to neutrality.

C) it fills column: ionic energy transfer column being filled it up with into edge on ultrapure water to splitter, adds 250 μ L AG1 ' 8 therewith Just entering splitter ramp after anion exchange resin sedimentation.

4, the separation and purifying of sample

1) primary to cross column

A) regenerate: sequentially adding 600 μ LHCl(6mol/L) -600 μ LH₂O(ultrapure water) -2 × 500 μ LHCl(6mol/L) - 3×500µLH₂O(ultrapure water) it is extremely neutral.

B) it balances: 500 μ LHBr(0.6mol/L).

C) sample loading: is transferred to 2mL centrifuge tube (through 10%HNO₃(ultrapure)) it is centrifuged in soaking and washing, draw centrifugation The 800 μ l drop of sample supernatant crossed is on resin.

D) it elutes: 3 × 500 μ LHBr(0.6mol/L).

E) Pb:1000 μ L HCl (6mol/L) is received in 7mL polytetrafluoroethylene (PTFE) cast bottle.

F) add 500 μ l HBr(0.6mol/L after sample solution is evaporated) it dissolves, this liquid waits for that ion exchange column is secondarily purified Pb。

2) secondary to cross column

A) regenerate: sequentially adding 600 μ LHCl(6mol/L) -600 μ LH₂O(ultrapure water) -2 × 500 μ LHCl(6mol/L) - 3×500µLH₂O(ultrapure water) (this step carries out during above-mentioned solution is evaporated).

B) it balances: 500 μ LHBr(0.6mol/L).

C) loading: 500 μ l drop of solution is on resin after drawing primary column excessively.

D) it elutes: 3 ' 500 μ LHBr(0.6mol/L).

E) Pb:1000 μ L HCl(6mol/L is received).

F) Milli-Q H2O washes out resin, and pitch tube is dipped in high-purity 6N HCl(6mol/L) in, standby next time uses.

5, the measurement of sample

1) rear sample will be isolated and purified to be evaporated in 120 DEG C on electric hot plate, 2mL 2%HNO is added₃Dissolution.

2) take appropriate solution that the 2%HNO of Tl isotopic standard solution is added₃(to correct fractionation factor) is diluted to 5mL, using SRM981 as standard test Pb isotopic ratio.

3) interference correction: being plasma carrier with Ar gas, due to argon gas when carrying out Pb isotope measure with MC-ICP-MS Containing micro Hg, exist²⁰⁴Hg pairs²⁰⁴The interference of Pb.Pass through measurement²⁰²Hg is used²⁰²Hg/²⁰⁴The natural abundance ratio of Hg, to detain It removes²⁰⁴Hg pairs²⁰⁴The contribution of Pb measuring signal.

4) fractionation factor corrects: using NBS982 as standard substance, marking to the isotopic composition of Tl solution used It is fixed.Sample Pb isotopic ratio is measured by internal standard of the Tl solution of calibration again.

Fractionation factor updating formula are as follows:

(²⁰⁸Pb/²⁰⁴Pb)_ture =(²⁰⁸Pb/²⁰⁴Pb) _meas ×(M ₂₀₈/ M₂₀₄)^f

In formula: subscript m eas and true respectively represent measured value and true value；M is quality；fFor the mass fractionation coefficient of Pb.

6, precision and accuracy

NBS981 measured value²⁰⁶Pb^/204Pb is 16.9338；²⁰⁸Pb^/204Pb is 36.6745；²⁰⁸Pb^/206Pb is 0.91453. NBS981 standard value²⁰⁶Pb^/204Pb is 16.9350 ± 0.01；²⁰⁸Pb^/204Pb is 36.6850 ± 0.02；²⁰⁸Pb^/206Pb is 0.91460±0.0002。

Sediments of Bohai Sea sample is determined using this method, checks that this method is accurate by the multiple measurement to same sample Degree RSD (²⁰⁸Pb/²⁰⁶Pb) < 0.13%, RSD (²⁰⁷Pb/²⁰⁶Pb) < 0.11%, RSD (²⁰⁶Pb/²⁰⁴Pb)<0.12%。

7, quality controls

Every batch of sample follows the repeating sample of process standard specimen BCR-2 and 10%, is spaced 3 sample test NBS981 in test process.

Six, points for attention

1) to prevent resin and sieve plate dry, experimentation must be completed at one day, and step interval must not exceed 30 minutes.

2) all reagents used in must make blank test before.The high reagent of blank, especially HCl is by serious shadow Ring the accuracy of method.

The above embodiments are merely illustrative of the technical solutions of the present invention, rather than is limited；Although referring to aforementioned reality Applying example, invention is explained in detail, for those of ordinary skill in the art, still can be to aforementioned implementation Technical solution documented by example is modified or equivalent replacement of some of the technical features；And these are modified or replace It changes, the spirit and scope for claimed technical solution of the invention that it does not separate the essence of the corresponding technical solution.

Claims

1. a kind of method for receiving Ratio of Lead Isotopes in inductivity coupled plasma mass spectrometry measurement deposit, feature exist more In: it the described method comprises the following steps:

2. the inductivity coupled plasma mass spectrometry that receives according to claim 1 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: the step 2 further includes being put into polytetrafluoroethylene (PTFE) cast bottle after the sample is removed carbonate.

3. the inductivity coupled plasma mass spectrometry that receives according to claim 1 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: the ionic energy transfer column the preparation method comprises the following steps:

4. the inductivity coupled plasma mass spectrometry that receives according to claim 3 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: the dropper material is LDPE, and the hydrophily sieve plate material is PTFE, and the aperture of the sieve plate is small In 50 microns.

5. the inductivity coupled plasma mass spectrometry that receives according to claim 3 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: the fill method of the ionic energy transfer column are as follows:

6. the inductivity coupled plasma mass spectrometry that receives according to claim 1 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: the primary specific steps for crossing column are as follows:

7. the inductivity coupled plasma mass spectrometry that receives according to claim 6 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: described secondary the step of crossing column are as follows:

8. the inductivity coupled plasma mass spectrometry that receives according to claim 6 or 7 measures Lead Isotope Ratios in deposit more The method of value, it is characterised in that: the solution used that elutes is 0.5 ~ 0.7mol/LHBr solution, is eluted 3 ~ 4 times.

9. the inductivity coupled plasma mass spectrometry that receives according to claim 6 or 7 measures Lead Isotope Ratios in deposit more The method of value, it is characterised in that: the concentration of the hydrochloric acid solution is 6 ~ 7mol/L.

10. the inductivity coupled plasma mass spectrometry that receives according to claim 1 measures Ratio of Lead Isotopes in deposit more Method, it is characterised in that: it is described to measure lead isotope in the prepare liquid using the inductivity coupled plasma mass spectrometries that receive more Ratio specific steps are as follows: